Lasers in dense gases pumped by low-energy electron beams

The use of low-energy (≈15 keV) electron beams for pumping laser systems in dense gases with high specific power deposition is described. Thin (300 nm) SiNx ceramic foils used as entrance window in a transverse geometry for the electron beam allows pressure differentials of several atmospheres with low percentage energy loss in transmission. The 1.73 μm XeI (5d[3/2]1–6p[5/2]2) infrared laser was used for a first demonstration of this concept. The laser operated between 130 and 650 mbar. A threshold pumping power of 5.3 W and a maximum output power of 6 mW were observed. The system can be scaled to high pumping power (≈MW/cm3) and short wavelength.